January ROC launch report

[rocwizard]

Today was ROC's monthly club launch. Man, what a great day for flying rockets! It was a bit chilly in the morning, about 36 or so, but it quickly warmed up to the the low high 60s. Clear blue sky with a couple little high altitude clouds here and there. And the best part, no wind! all the way till when the launch closed down about 4:45 or so we had great weather.

Lots of midpower, and low high power, quite a few Js, and 2 beta flights on the RATT Works K350 tribrid. THEY ARE AWESOME, to say the very least.

One inparticular was David's Laser LOC 2.1 that he flew on a J570. Really awesome on the up part. broke Mach very quikly on it was up to 9308 feet per the ARTS. The problem was when the rocket deployed a little late cause of a bug in the ARTS unit which made for a small (1-1.5") zipper in the booster, as well as separating the booster and the payload sections, leaving the payload section with the chute. The booster did the flat spin thing and got a couple repairable dings in it. The payload now had a very oversized chute coming down form 9000 feet at like 5 feet a second. It drifted off the lakebed in to the surrounding sagebrush. very hard to see rockets in this stuff. To make a long story short, it was found undamaged after about 4.5 hours of searching, hiking up hills, driving down endless fire roads, and getting shot at by the local desert wackos :kill: No kidding!

The big highlight of the day was when Jeff A. flew is beautiful Nike Ajax. It was a collaborative effort of many of the ROC members, including myself and David, to get it into the air before dark, and the waiver closing. The sucker was 7.5" in diameter in the lower section and 6" in the upper. It was powered with 4 yes FOUR K700Ws and a central K1275R. The first second after ignition is burned into my mind. A massive Nike Ajax belching out a good 12 foot reddish WL flame and a whole lotta smoke!. After that though things got crazy. One of the K700s blew its forward closure and bunrt a coupla large holes in the booster. The burning grains started pourning out the side of the rocket as it was was horizontal coming out of doing a corkscrew. The booster is dead, but the two forwards airframe sections are unscathed as the flaming rocket fully deployed its chutes bring the parts safely to the ground!According to lakebed standards, it can be chalked up as a successful flight.

David got some pics and video of the Ajax, so i'll get him to post them soon

 

[rocwizard]

forgot to mention that i saw several deuce and tres out here flying. One person flew their deuce on two D24s, cool flight!

Just had to let jim know us californians like your kits

 

[n3tjm]

Originally posted by rocwizard
David got some pics and video of the Ajax, so i'll get him to post them soon

You betta! Or you might get a visitor late at night :kill:



Can't wait to see the video

 

[jflis]

Originally posted by rocwizard
forgot to mention that i saw several deuce and tres out here flying. One person flew their deuce on two D24s, cool flight!

Just had to let jim know us californians like your kits

*wonderful*

Would love to see pix of other Tres flying! can't wait for that

 

[daveyfire]

Yes, such a day, such a day...

I had planned to fly three rockets: my Laser/LOC 2.1 on a J570W, my Pull My Finger on a K240H, and my Arcas on a K550W. Well, the best laid plans of mice and men... you know the rest...

I got the Laser/LOC all prepped and ready to fly. It was on the pad at around 11:00 or so, and we called in the high altitude waiver, pushed the button and let 'er rip. After a couple seconds of delay, the motor lit up and WOW that thing moved. I've got video capture at 30 frames/second and the rocket is visible in the frame for three seconds. It went mach at 400 feet at one second into the burn and stayed there for two seconds. Everything looked great until deployment, at which point one spotter I had on it said he saw separation. Apparently, the firmware fix in the ARTS didn't help very much, and the rocket deployed five seconds after apogee. Ugh. Gotta get that one fixed. But the upside is that the ARTS seemed to notice that... it said max baro altitude was detected 5 seconds before max accel altitude, at which point it fired the charge. That's odd because the flight was straight up...

Oh well, that was the least of my worries at the time. We had to go out and get the rapidly disappearing payload section on the (now way oversized) 28" parachute. The booster had landed quickly and was visible from the launch site. I drove out to get the booster while my dad started walking in the direction of the payload section. We recovered the booster quickly and only with minor damage, the zipper Eric mentioned and a small kink in the tube right above where the motor casing and glass wrap ended. Did I mention that I sent an unreinforced cardboard rocket through Mach? The booster's shock cord was snapped clean off at the end, or at least as clean as flat nylon snaps. Obviously a late deployment.

So we had the booster, with the motor casing and my nifty boat tail adapter, back in hand. But the payload section was another story. My dad was hiking all around in the dunes and the scrub brush on the edges of the lakebed (over 2 miles from where we were flying) with no sign of the payload section. Eric and I drove over to a small hill overlooking the recovery zone, but couldn't see anything because of the scrub brush. The best we could do was a foot search on the ground, which took until almost 3:30. In the meantime, we learned that scrub brush hides parachutes very well and that the yokels in the desert will SHOOT you if you walk on their property We did eventually find it, beeping away happily behind a bush, all but hidden from sight. Suffice to say, I didn't fly anything else that day. But my one flight was COOOOOOOL. After downloading the data on the way home, the ARTS recorded a maximum acceleration of 39 gees and a maximum velocity of 1342 fps. There are two neat spikes in the pressure data as the rocket went through and came back out of Mach. And I got it all back with very little damage. Meaning I'll be trying this again soon!

The other flight of the day that Eric and I both helped out with was the giant Nike-Ajax. Let me state that I believed this project would never make it to the pad, as the flyer had just certified level two that same day, and he didn't even start prepping the bird until about 2:30, when the motors showed up. So he turned to Wedge Oldham (you know, the Nike Project guy) for certification and support, and about five other guys from the club to help prep the bird. We put it on the pad just before sunset. Eric and I got to insert and wire up the igniters, which for five 54mm motors was no small task. They armed the electronics, Wedge hooked up the clips, and we backed off to a safe distance. My dad remained at the middle row (~200 feet away) to video. After the usual banter regarding a big flight like this, Ron McGough gave the ten count and hit the button. The rocket thought about it for about a second then screamed off the pad in both senses of the word -- the resonance of the four K700s and the K1275 burning all at the same time gave the rocket a high pitched SCREAM as it left the pad. Woo hoo, Eric and my part worked! Then, right off the rail, was the first sign of a problem. One of the K700s had an o-ring fail at the forward closure, causing a sizeable flame to come out of the side of the rocket near the tops of the motors. Then things got ugly. The neutrally stable Ajax, with one motor out, turned over sideways and began to do loops. It did one and a half loops and then proceeded to deploy all of the chutes, spitting out K700 grains as it went. Quite a dramatic moment. The sustainer came back unscathed, but the booster. Oh the poor booster. Walking out to it, Wedge asked, "Is it just me, or can I see daylight through the booster?" Yup. There was a hole burned all the way through the midsection of the booster, right where the K700 turned itself into an aluminum potato chip. It was a sad ending to a really cool start. But the rocket did get into the air, and the sustainer came back unscathed, ready for more. I hope Jeff rebuilds it and flys it again!

I didn't notice too many other flights during the day, but I remember the RATT Works Tribrid in particular, both times. Dave's been testing out his new creations at our launches lately, and two flights were made on the new tribrid system. The first one I didn't see, but I heard from really far away while I was looking for my Laser/LOC. The second one I got to see up close and personal. Dave added Copper Carbonate to the grains, so they burned with a green flame on the way up before the alcohol transition. They were LOUD off the pad, then a quick pop and they transitioned to biprop mode, where they just cruised off on an incredibly long burn. Everyone needs to get one of these when they get cert'ed! Joe Mullin also static tested a RATT L motor with superheated nitrous. Being Joe, he set it all up on his test stand, then taped a hair dryer to the side of the nitrous tank to heat it up during the burn. It was a quick, loud burn for about 3 seconds, then had about another 3 seconds of blowdown. The peak thrst measured was nearly 450 lbs, with total newton seconds around 3300. Interestingly enough, when he took apart the motor, none of the plastic fuel grain had been consumed. It appears that all of the thrust had come from the decomposition of the nitrous oxide. This was very interesting, possibly allowing the fuel grain volume to be reduced and the total impulse of the motor to be increased. Too cool.

The day was perfect and beautiful, temps in the 70s with no wind all day. As the sun set over the mountains, the desert turned surreal shades of blue, orange, and pink. What a way to start out the new year!

Pics at: https://tinyurl.com/39t9m, I've attached a photo of the Nike/Ajax liftoff to entice you!

 

[daveyfire]

P.S. : I'm too cheap to buy server space. I've got videos of the Nike/Ajax and my Laser/LOC, or as much as we could get of it Anybody got server space they're willing to lend?

 

[cls]

hey folks, some OK video of the Nike Ajax here

https://home.comcast.net/~cls44/

 

[rocwizard]

that would be the one! Thanks for poting that! man, after seeing it again, i am reminded just how awesome that was. Not so awesome for Jeff tough

 

[cls]

this image is somewhat washed out and the angle isn't quite right so you can't exactly see the 3rd fins & motor ... but here is Tres #19 blasting off.


obFlisContent: #19 flew 3 times; my Deuce's Wild flew 3 times. Richter Recker flew 1 time on a pack of E9-6s perfectly. my upscale USS Grissom flew on an E9-6 with a heart stopping 2 seconds too long delay. the Nomad flew perfectly on D12-0 C6-0 C6-7. thanks to my best man Charles for biking to the store to get D12-0s - ya gotta love a desert launch site with a hobby shop/hardware store/grocery store within easy biking distance!!

 

[rocwizard]

So that was you i saw walking around with that white Tres! Had i known you were a forum member, i would have stopped over and introduced myself. I will be sure to at the next launch. Look forward to meeting you.

Great flights of your Tres btw!

 

[cls]

here's my son Aidan with his xmas present ... "before"

 

[rocwizard]

Ouch, that one was a bummer. The fwd closure let go huh?

 

[cls]

and here he is with some of the remains ... "after"


looks like the World's Worst Dad musta built that I161 wrong. I can't figure out how, but we had incredible flames coming out ... "forward closure failure" ... maybe I switched the top o-ring and the fiber washer??

we're already talking about how to rebuild it.

 

[cls]

Hey RocWizard! (sorry for the interleaved postings here)

I think we ought to make it a requirement to wear TRF T-shirts or something. or maybe fly a flag at our command posts.

really sorry I missed you. "next time" eh?

Cliff

 

[NewEntity1]

I started heading back just shortly after 3:00 pm on Saturday, so I missed the Nike/Ajax launch, unfortunately, but I saw lots of other cool launches

Unfortunately, mostly all I got pictures of were smoke trails...my camera is too slow.

Here is the first smoke trail...I don't remember what rocket it was from anymore. Something big, heh...

 

[NewEntity1]

Oh look, another smoke trail

This was a mid-sized rocket, I think...

 

[NewEntity1]

Here is a picture of some of the peaple camped out around the area...

 

[NewEntity1]

This is one of the few truly good imeges I captured...I timed it just right ( I snapped the shutter two seconds BEFORE the rockets were launched..the LCO had just barely started counting down). It was a drag race, and I managed to get on of the rockets in the air in the image.

 

[NewEntity1]

This was an interesting looking rocket. Later on I saw it fly, and it was sweet! It slowly spiraled as it climbed

I'm gonna have to build me one of these sometime. Does anyone know what kit this is?

 

[NewEntity1]

Here is a picture of a really large rocket at it's camp. I never saw it fly though...it must have flown either before I arrived, or after I left.

 

[NewEntity1]

Here is a picture of the color blue. No, actually its a rocket captured on descent. I no longer remember what this was, either. Next time I'll have to take notes

 

[NewEntity1]

A large rocket being checked in. It flew on a J350 I think. Very nice

If someone knows who this is, they might be able to correct me though, and tell me what kit this is, or if its a scratch built.

 

[NewEntity1]

I had a few other pictures, but they mostly consisted of the color blue with tiny white dots in the center, so I figured they were not worth posting

 

[NewEntity1]

Oops I forgot about this one....the great tilted rocket. Despite the angle, the Bertha mod flew successfully on this launch. It was its second launch (where it went straight up) that it separated...

BTW, I met and spoke with cls with his tres 19
I didn't know it was cls, of course, and he had no idea I was NewEntity

 

[cls]

newentity1 posted:

This was an interesting looking rocket. Later on I saw it fly, and it was sweet! It slowly spiraled as it climbed

I'm gonna have to build me one of these sometime. Does anyone know what kit this is?

that's my upscale Tristar. I posted a thread about building it, including the rocksim file for it, here:

https://www.rocketryforum.com/showthread.php?s=&threadid=5097

we flew it twice, both times on 29mm H238s 'cos that's all I had and the vendor hadn't shown up yet.


we flew the little one too it blasts on C6-5s.

 

[Rocketman248]

NewEntity, if you have a digital camera, usually if you push and hold the shutter button down about halfway, it will focus. Then, if you push it down all the way, it will take the pic amost instantly.

That Nike Ajax was awesome! Four K700s and a K1275 make an N4075! Sweet! Man, I wish I could have seen that. The liftoff was awesome! How big was it? Length, diameter, weight?

 

[Loki]

Originally posted by daveyfire
Yes, such a day, such a day...

<snip>

Apparently, the firmware fix in the ARTS didn't help very much, and the rocket deployed five seconds after apogee. Ugh. Gotta get that one fixed. But the upside is that the ARTS seemed to notice that... it said max baro altitude was detected 5 seconds before max accel altitude, at which point it fired the charge. That's odd because the flight was straight up...

David,

Could you please send me the .odf data file from this flight? We've logged a bunch of flights now on the v1.41 ARTS firmware and not had any early or late deployments, so I'm anxious to see what happened on your flight.

The issue isn't a "bug" in the traditional sense. Originally the ARTS was rounding off the acceleration values during its in flight calcualtions to lighten the processing load. This was intentional and in our initial testing did not cause any problems. However, now having many many more flights logged we did find some examples of reduced accuracy in the apogee detection (early and late). Additional testing showed that our original concern about over loading the CPU was unfounded and the v1.41 firmware now does all calculations at full precision.

I suspect if you flight had a problem, that it is unrelated to the above issue. I won't be able to tell until I see the data.

Sounds like you guys had a great launch! Keep up the good flights!

-Jeff Taylor
Loki Research

 

[rocwizard]

Hey Jeff welcome to the forum! Just to let yuo know if you haven't picked up on this, we here on TRF like pics. So keep that in mind when posting

We hope you enjoy it here cause we actually talk rockets, so you dont have to worry about politics or flame wars

 

[daveyfire]

Jeff -- good to see you here! Your customer support is great. I'll send the data right over. It's interesting to note that in the file, the pressure spikes that occurred as the rocket passed in and out of mach coincide exactly with the velocity data, however the barometric and accelerometer altitudes differed from each other by 2000 feet and five seconds. The one spotter who had a track on the rocket at apogee said he saw it arc over and begin to descend for 4-5 seconds before firing the charge. Having not checked out the ARTS beforehand, I assumed it to be something with the firmware. But ya never know! Let me know if there's something I can do to prevent this in the future. All in all, however, I LOVE the ARTS unit and recommend it to everyone!

P.S. I posted video of the Nike-Ajax at https://home.earthlink.net/~daveyfire/nike ajax.wmv . This was shot from the middle row of pads by my dad... he's getting good at this stuff!

 

[Loki]

Wow! What happened to that one?

-JT